JP2005509957A6 - Data carrier for transmitting data with different transmission parameters - Google Patents

Abstract

An improved data carrier, an improved circuit for the data carrier, and an improved communication station are provided and using these data carriers, the communication stations of these data carriers substantially. Always ensure the fastest and most complete query and detection of each data carrier, regardless of distance from and without incurring such high costs.
A data carrier (1) for performing contactless communication with a communication station includes a reception stage (3) for receiving an inquiry signal (IS), and second, an inquiry signal ( A generation stage (17) for generating a response signal (RS) as soon as (IS) is received, and third, to process the response signal (RS) into a transmission signal (MCRS) suitable for transmission to a communication station A processing circuit (18), and fourth, a decision device (22) for determining at least one representative value (REP1, REP2) representative of the field strength of the field acting on the data carrier (1), Fifth, it has a control coupling unit (25) between the determination device (22) and the processing circuit (18), and at least one representative of the transmission parameters of the transmission signal generated by the processing circuit (18). In order to vary as a function of the values (REP1, REP2), the processing circuit (18) can be influenced via the control coupling (25).

Description

The present invention is aimed at and designed to do contactless communication with a communication station, and for this purpose can be generated by the communication station and is produced by the communication station and acts on the data carrier A data carrier having receiving means for receiving an interrogation signal that can be transmitted to the data carrier in a contactless manner by the field,
Generating means for generating a response signal as soon as the inquiry signal is received;
Processing means for processing the response signal, wherein the response signal is processed into a transmission signal suitable for transmission to the communication station, and at least one transmission parameter of the transmission signal can be changed therein;
Relates to a data carrier having

The present invention further provides:
A coupling means for receiving the inquiry signal;
Generating means for generating a response signal as soon as the inquiry signal is received;
Processing means for processing the response signal;
And a data carrier circuit for contactless communication with a communication station.

  The invention further relates to a communication station for contactless communication with a data carrier according to the design described in the first paragraph above.

The data carrier according to the design described in the above first paragraph and the circuit according to the design described in the above second paragraph are disclosed in, for example, Patent Document, International Patent Publication No. WO99 / 65168. The design of this known data carrier with this known circuit is
Processing means for processing the response signal is formed within a plurality of different time windows; and
The time window within which this known data carrier generates its transmission signal formed from the response signal and transmitting this transmission signal to the communication station is important for this data carrier. It is determined as a function of part of the serial number.

  For data carriers designed to process the response signal within a plurality of time windows, the processing means is recognized as the latest technology in the aforementioned patent document, International Patent Publication No. WO99 / 65168, See U.S. Pat. No. 5,539,394. In the case of the data carrier disclosed by the above-cited International Patent Publication No. WO99 / 65168 and US Pat. No. 5,539,394, a communication station for transmission signals transmitted from the data carrier to the communication station A processing means is provided in which the starting point of the time window at which transmission to can be performed is selected as a variable transmission parameter.

  However, it is also possible to select the subcarrier signal as a variable transmission parameter. In this case, the associated data carriers are designed to generate different subcarrier signals and are designed to generate subcarrier signals with different subcarrier frequencies and those subcarriers with different subcarrier frequencies. The signal is preferably used for modulation of the response signal in order to generate a transmission signal suitable for transmission to the communication station. In this regard, reference can be made to the patent document US Pat. No. 5,485,154.

Common to all of the known data carriers mentioned above is that the generation of the response signal and thus the generation of the transmission signal is a serial number part stored in the memory of the known data carrier, or a random number part, or The fact is that it depends only on other memory content parts. In the case of a known data carrier, this means that there are multiple data carriers in the communication range of the communication station, so that two data carriers use their transmission parameters with the same transmission parameters. Transmit to a communication station (eg, using the same time window), one of these two data carriers is probably located relatively close to the communication station, and the other data carrier is relative to the communication station By being far away,
A data carrier located relatively close to the communication station transmits a relatively strong transmission signal to the communication station,
The problem that a data carrier located relatively far from a communication station can transmit only a relatively weak transmission signal to the communication station can occur relatively frequently. This means that the transmission signal of the data carrier located relatively close to the communication station masks the transmission signal of the data carrier located relatively far from the communication station. Data carriers located far away are not subsequently detected by the communication station, and no further processing (eg selection, reading, or writing) can be done when the need arises later Unfortunately, and often unfortunately this actually means this. This situation can cause a failure situation or increase the cost of detecting all data carriers located within the communication range of a communication station to eliminate such a failure situation. There is sex.

International Patent Publication No. WO99 / 65168 U.S. Pat.No. 5,539,394 U.S. Pat.No. 5,485,154

  The object of the present invention eliminates the above-mentioned problems and provides an improved data carrier, an improved circuit for the data carrier, and an improved communication station, using these data carriers, The fastest and most complete query and detection of each data carrier is always ensured regardless of the distance of these data carriers from the communication station and without incurring such high costs. It is to be.

  The foregoing objects are achieved within the data carrier of the present invention by providing the features of the present invention such that the data carrier of the present invention is characterized as follows.

A data carrier for contactless communication with a communication station, the means listed below:
Receiving means for receiving an inquiry signal that can be generated by the communication station and that can be transmitted to the data carrier in a contactless manner by a field that is generated by the communication station and that acts on the data carrier;
Generating means for generating a response signal as soon as the inquiry signal is received;
The response signal is designed to process the response signal into a transmission signal suitable for transmission to the communication station, and at least one transmission parameter of the transmission signal can be changed therein. Processing means for
Determining means for determining at least one representative value representative of the field strength of the field acting on the data carrier;
Designed to controllably influence the processing means as a function of the at least one representative value, i.e. to change at least one transmission parameter of the transmission signal as a function of the at least one representative value. A control coupling means between the determining means and the processing means;
Having a data carrier.

  The foregoing objects are achieved within the circuit of the present invention by providing the features of the present invention such that the circuit of the present invention is characterized as follows.

A circuit for a data carrier for performing contactless communication with a communication station, the means listed below:
A field that can be generated by the communication station and created by the communication station and acting on the data carrier can be transmitted to the data carrier in a contactless manner and therefore transmitted to the circuit for the data carrier A coupling means for receiving possible inquiry signals;
Generating means for generating a response signal as soon as the inquiry signal is received;
The response signal is designed to process the response signal into a transmission signal suitable for transmission to the communication station, and at least one transmission parameter of the transmission signal can be changed therein. Processing means for
Determining means for determining at least one representative value representative of the field strength of the field acting on the data carrier;
Designed to controllably influence the processing means as a function of the at least one representative value, i.e. to change at least one transmission parameter of the transmission signal as a function of the at least one representative value. A control coupling means between the determining means and the processing means;
A circuit for a data carrier for performing contactless communication with a communication station.

  By providing the features of the present invention, a transmission signal suitable for transmission to a communication station is formed as a function of at least one representative value representative of the field strength of the field acting on the data carrier of the present invention, Only simple means and a small additional cost ensure it. This allows data carriers that are located relatively close to the communication station and thus generate representative values representative of high field strength to operate within the specified range of transmission parameters, while relatively far from the communication station. It is easily possible for other data carriers of the present invention that are located farther away and thus generate representative signals corresponding to relatively weak field strengths to operate within different ranges of transmission parameters. This ensures that data carriers exposed to different field strengths always generate their transmission signals within different ranges of variable transmission parameters. This means that only data carriers that are exposed to essentially the same field strength will be able to operate within the range of variable transmission parameters, so any such as may occur with known data carriers. The masking effect is also eliminated in the case of the data carrier of the present invention.

  It has been found to be particularly advantageous if the data carrier of the present invention is further provided with the features of claim 2 and the circuit of the present invention is further provided with the features of claim 7. The reason why such an embodiment is particularly advantageous is that, if necessary, the control means capable of generating control data makes it possible to control the processing means very diversely as a function of at least one representative value. It is. However, what should be mentioned at this point is that in the simplest case, even if no control means is provided, it is formed by a simple electric or electronic coupling provided between the determining means and the processing means at this time. It is also possible to manage the control coupling means that are present, and this control coupling means can help to send the control commands emitted by the decision means directly to the processing means.

  It has been found to be advantageous if the data carrier of the present invention is further provided with the features of claim 3 or if the circuit of the present invention is further provided with the features of claim 8. . From such an embodiment, the response signal is processed into a transmitted signal within a time window starting at a specific starting point that is a function of the field strength to which the inventive data carrier with the inventive circuit is exposed. Benefits are gained.

  It has also proved to be advantageous if the data carrier according to the invention is additionally provided with the features according to claim 4 or the circuit according to the invention is additionally provided with the features according to claim 9. Yes. This is because the coding method implemented when processing the response signal into the transmission signal is selected as a function of at least one representative value so that the particular coding method selected has the circuit of the present invention. Fig. 3 represents a simple way of ensuring that it varies as a function of the field strength acting on the data carrier of the present invention.

  However, it is also very advantageous if the data carrier of the present invention is further provided with the features of claim 5 or if the circuit of the present invention is further provided with the features of claim 10. Is known. From such an embodiment, the subcarrier signal that may be necessary to process the response signal into a transmission signal is adapted to at least one representative signal with respect to the subcarrier frequency of this subcarrier signal. And thus the advantage is obtained that it can be adapted to the field strength acting on the data carrier of the invention with the circuit of the invention.

  The foregoing objects are achieved within the communication station of the present invention by providing the features of the present invention such that the communication station of the present invention is characterized as follows.

A communication station for contactless communication with a data carrier,
The data carrier is designed for contactless communication with the communication station and means listed below:
Receiving means for receiving an interrogation signal that can be generated by the communication station and that can be transmitted to the data carrier in a contactless manner by a field produced by the communication station and acting on the data carrier;
Generating means for generating a response signal as soon as the inquiry signal is received;
The response signal is designed to process the response signal into a transmission signal suitable for transmission to the communication station, and at least one transmission parameter of the transmission signal can be changed therein. Processing means for
Determining means for determining at least one representative value representative of the field strength of the field acting on the data carrier;
So as to controllably influence the processing means as a function of the at least one representative value, i.e. to change the at least one transmission parameter of the transmission signal as a function of the at least one representative value. A designed control coupling means between the determining means and the processing means;
Have
The communication station has the following means:
Command signal generating means for generating a command signal;
Receiving means for receiving the transmission signal transmitted from the data carrier to the communication station;
Processing means for processing the received transmission signal;
Transmission parameter detection means for detecting the transmission parameter of the received transmission signal;
An object is to make a decision to interact with the transmission parameter detection means and to generate at least one command signal as a function of the transmission parameters of the received transmission signal detected by the transmission parameter detection means. And a determination means designed in such a way;
A communication station for performing contactless communication with a data carrier.

  Providing the features of the present invention in the communication station of the present invention exceeds the specified minimum field strength determined by the determining means in the data carrier, and transmission parameters of the transmission signal from the data carrier to the communication station Only if the data carrier that is responsible for generating the command signal is exposed to the field strength represented by the representative value generated in the data carrier, It is a simple way to ensure that the generation is permitted by the decision means, i.e. it is possible with only a small additional cost. By this method, for example, only when the access control data carrier is in proximity to the communication station, the access clearance command signal for the door, for example, in the access control system having the communication station of the present invention, It is easily and advantageously ensured that it is generated by a host computer.

  It has proved to be particularly advantageous if the communication station according to the invention is further provided with the features of claim 12. This is due to the fact that the associated data carrier is sufficiently close to the communication station so that it is exposed to a relatively high field strength and as a result is provided with a relatively high power. A so-called write command signal represents a simple and advantageous way in which the command signal generating means of the communication station according to the invention can generate it. This is due to the fact that the associated data carrier is sufficiently close to the communication station of the present invention and is only relatively constrained to the computer if it is supplied with sufficient power. It is a simple way to ensure that so-called security functions in the data carrier that require power are also activated by corresponding command signals in the data carrier.

  The foregoing and other aspects of the invention will be apparent from and will be elucidated with reference to the embodiments described hereinafter and with reference to these embodiments.

  The invention will be further described with reference to the embodiments shown in the drawings. However, the present invention is not limited to these examples.

  FIG. 1 shows a first embodiment of a data carrier 1 according to the invention with a circuit 2 for the data carrier 1. Circuit 2 is an integrated circuit. The data carrier 1 is intended to perform contactless communication with a communication station not shown in FIG. 1 and is designed as such. In this case, data carrier 1 is coupled to a product and data relating to this product (eg, product type, sales price, date of manufacture, warranty validity date, and similar characteristics) is stored therein Carrier 1. However, the data carrier 1 may be intended for and designed for other uses. If necessary, the communication station can retrieve data stored in the data carrier 1 via contactless communication between the data carrier 1 and the communication station. In order to perform such contactless communication completely, the communication station has to allow further processing of the data carrier 1 (for example writing to or reading from the data carrier) It must be possible to detect the data carrier 1 completely, and for many applications it should also be possible to select from several such data carriers. In order to fully detect the data carrier 1 using the communication station, the data carrier 1 has a series of means. These means are discussed in more detail below. It should be mentioned that only important means are shown in FIG. 1 herein. Data carrier 1 includes several other means not discussed further herein.

  The data carrier 1 has transmission means 3 forming both reception means and transmitter means. The transmission means 3 includes a transmission coil 4 provided outside the circuit 2 and a capacitor 5 included in the circuit 2. The transmission coil 4 is coupled to the contact terminal 6 of the circuit 2, which forms an integral part of the circuit 2 coupling means. The transmission coil 4 and the capacitor 5 form a resonance circuit, and the resonance frequency of the resonance circuit corresponds to the operating frequency of at least one signal transmitted from the communication station to the data carrier 1. In this case, the signal transmitted to the data carrier 1 is an amplitude-modulated carrier signal MCSIS. However, this signal transmitted on the data carrier 1 may be some other form of transmission signal.

  The transmission means 3 forming the receiving means are intended to receive the inquiry signal IS contained in the carrier signal MCSIS which is amplitude-modulated and are designed as such. The interrogation signal IS can be generated by a communication station (not shown) and can be transmitted to the data carrier 1 in a contactless manner by a field produced by the communication station and acting on the data carrier 1. In this case, the transmission is by inductive means or transformers. However, instead of this, the transmission may be by electromagnetic means. The inquiry signal IS requests a data carrier 1 or several data carriers 1 existing within the communication range of the communication station to report to the communication station, that is, to transmit a response signal to the communication station.

  Data carrier 1 and circuit 2 have a power supply circuit 7 having a limiting stage 8, a clock pulse regeneration stage 9, and a demodulation stage 10. The power supply circuit 7, the clock pulse regeneration stage 9, and the demodulation stage 1 are each coupled to the contact terminal 6, so that the modulated carrier signal MCSIS is sent to each of these circuit elements.

  As has long been known technology, the power supply circuit 7 is intended to generate a DC supply voltage V using the amplitude-modulated carrier signal MCSIS sent to it, and is designed as such. Yes. The power supply circuit 7 has a limiting stage 8, which can limit the generated DC supply voltage V to a specific value. Providing such a limiting stage 8 in such a data carrier 1 or in a power supply circuit 7 in such a data carrier 1 has long been known. As a result of the limiting function of the limiting stage 8, a limiting current IL is generated in the limiting stage 8, as indicated by the symbol in FIG.

  The clock signal regeneration stage 9 is intended to regenerate the clock signal CLK using the carrier signal MCSIS which is amplitude-modulated and is designed as such. This means has also been known for a long time.

  The demodulation stage 10 is intended and designed to demodulate the carrier signal MCSIS that is amplitude modulated. The amplitude-modulated carrier signal MCSIS can be sent to the demodulation stage 10, so that the demodulation stage 10 can generate and send the demodulated carrier signal CSIS. A decoding stage 11, to which the demodulated carrier signal CSIS can be sent, and to which this still coded signal can be decoded, is coupled to the output side of the demodulation stage 10. This signal is coded in advance in a communication station (not shown). After decoding, the decoding stage 11 emits an inquiry signal IS.

  The means described so far become operational when data carrier 1 is in reception mode. However, the data carrier 1 also enables a transmission mode from the data carrier 1 to the communication station. For this purpose, data carrier 1 or circuit 2 comprises a coding stage 12, a modulation stage 13 coupled to the output side of the coding stage 12, and a subcarrier signal generator 14 coupled to the modulation stage 13. Have. The modulation stage 13 is coupled to the output side of the contact terminal 6 and is therefore coupled to the transmission means 3. This transmission means 3 also forms a transmitter means. A response signal RS can be sent to the encoding stage 12. The generation of the response signal RS will be discussed in more detail below. The response signal RS is encoded by the encoding stage 12, which can emit the encoded response signal CRS after encoding. The encoded response signal CRS can be sent to the modulation stage 13. The subcarrier signal SCS generated by the subcarrier signal generator 14 can also be sent to the modulation stage 13. The modulation stage 13 performs amplitude modulation of the encoded response signal CRS using the subcarrier signal SCS. As a result, the modulation stage 13 sends the amplitude-modulated and encoded response signal MCRS to the transmission means 3, and the transmission means 3 performs transmission to the communication station. However, phase modulation or frequency modulation may be executed instead of amplitude modulation.

  The data carrier 1 and the circuit 2 of the data carrier 1 have a microcomputer 15. However, instead of the microcomputer 15, a wired logic circuit may be provided. As has long been known, storage means 16, including RAM, ROM, and EEPROM, interacts with microcomputer 15. The microcomputer 15 is provided with data processing means 17. The data processing means 17 functions to process the received inquiry signal IS and further generates a response signal RS as soon as the inquiry signal IS is received or in response to the received inquiry signal IS. To work. Accordingly, the data processing means 17 also forms generating means 17 for generating a response signal RS in response to the received inquiry signal IS, in addition to some other means (not shown). A response signal RS is generated from the data contained in the storage means 16 and characterizing the data carrier 1.

  The data carrier 1 and the circuit 2 further include processing means 18 for processing the response signal RS. The processing means 18 processes the response signal RS into a transmission signal suitable for transmission to the communication station 1, that is, a modulated and coded response signal MCRS. The transmission parameters of this transmission signal can be changed in the processing means 18. In this case, the processing means 18 for processing the response signal RS is formed in a total of 64 time windows TW starting at 64 different starting points, as indicated by the symbols in FIG. However, it is also possible to select a different number of time windows, for example starting at 32 or 128 or 256 or alternatively some number of different starting points which is not a multiple of 2. In order to define a time window TW starting at 64 different starting points, the processing means 18 has a time window defining means 19 provided in this case by the microcomputer 15. The response signal RS generated by the data processing means 17 can be sent to the time window definition means 19, and the time window definition means 19 then relays the response signal RS to the coding stage 12 therein, Define a specific time window TWn. It should be further noted that the processing means 18 comprises a time window definition means 19, a coding stage 12, a modulation stage 13 and a subcarrier signal generator 14.

  A first analog / digital converter 20 and a second analog / digital converter 21 are provided in the data carrier 1 and the integrated circuit 2. Since the first analog / digital converter 20 is coupled to the output of the power supply circuit 7 on the input side, the first analog / digital converter 20 generates the first digital value DV representing the DC supply voltage generated at this output. Can be generated. Since a voltage VIL proportional to the limit current IL generated in the limit stage 8 can be sent to the second analog / digital converter 21, this voltage VIL is represented and, as a result, the limit current IL is representative. The two digital value DVIL can be generated by the second analog / digital converter 21.

  The microcomputer 15 implements a decision means 22 that can send the first digital value DV and the second digital value DVIL. The decision means 22 is intended and designed to determine two representative values REP1 and REP2, each representing the field strength of the field acting on the data carrier 1. The determination means 22 has a voltage value determination stage 23 and a current value determination stage 24. The voltage value determination stage 23 generates a first representative value REP1 having a relationship with the supply DC voltage V using the first digital value DV. The current value determination stage 24 generates the second representative value REP2 having a relationship with the limit current IL in the limit stage 8 by using the second digital value DVIL. Due to the existence of these relationships, these two representative values REP1 and REP2 represent the field strength of the field acting on the data carrier 1. As a result, information indicating the level of field strength acting on data carrier 1 and thus the distance from the communication station to data carrier 1 is obtained via these two representative values REP1 and REP2. Included in 1.

  Advantageously, the control coupling means 25 is provided between the determining means 22 in the data carrier 1 and the processing means 18 in the integrated circuit 2. The control coupling means 25 makes it possible to influence the processing means 18 as a function of two representative values REP1 and REP2. The purpose of the control influence on the processing means 18 is here to change at least one transmission parameter of the transmission signal as a function of two representative values REP1 and REP2. In this example, the starting point of the time window TW forms a variable transmission parameter. That is, in the case of this example, 64 starting points for a total of 64 time windows TW can be defined as a function of two representative values REP1 and REP2.

  Within the control coupling means 25 in each of the data carrier 1 and the circuit 2, there is provided a control means 26 that can interact with the decision means 22 and send two representative values REP1 and REP2 to it. Yes. The control means 26 is designed to generate the control data CDA as a function of two representative values REP1 and REP2, and in this case one transmission parameter is to be changed by the generated control data CDA And interact with the processing means 18.

  The control means 26 has a data generator 27 in this case in the form of a random number generator. The purpose of this random number generator is to generate random numbers. These random numbers can influence the selection of the time window, ie the selection of the start point of the time window. However, the so-called serial number of the data carrier 1 is sent from the storage means 16 to the data generator 27 via the coupling 28 shown schematically and data generation from this serial number sent to the data generator The data generator 27 may be designed such that the generator generates data and this data can influence the selection of the time window, ie the selection of the starting point of the time window. The control means 26 uses the two representative values REP1 and REP2 and the random number generated by the random number generator 27, and the control data that can be sent from the control means 26 to the time window definition means 19 via the coupling unit 29. CDA can be generated. The start point of the time window TWn is defined by the control data CDA, the response signal RS generated by the data processing means 17 is relayed to the coding stage 12 within this time window TWn, and then modulated and coded The response signal MCRS can be transmitted from the data carrier 1 to the communication station 1.

  When data carrier 1 and circuit 2 generate two representative values REP1 and REP2, each representing the high field strength of the field acting on data carrier 1, time window TW (where data carrier 1 is the response The signal RS is generated and this response signal RS is then transmitted to the communication station as the transmission signal MCRS), such transmission occurs only during the first 32 possible time windows TW Designed not to be defined. On the other hand, if the two representative values REP1 and REP2 substitute for the weak field strength of the field acting on data carrier 1, data carrier 1 or circuit only during the second 32 time windows TW The result is that no transmission occurs within 2. This ensures that data carrier 1, which is exposed to changing field strength values, always transmits these response signals to the communication station in different time windows, so that weak response signals from the data carrier are separated. Is never masked unnecessarily by strong response signals from other data carriers, and it is therefore simple to fully detect all data carriers that are within the communication range of the communication station. Secure by means.

  The data carrier 1 and the circuit 2 in FIG. 2 have almost the same design as the data carrier 1 and the circuit 2 in FIG. However, a different design has been selected for the processing means 18 in the data carrier 1 of FIG.

  In the case of the data carrier 1 and the circuit 2 in FIG. 2, the processing means 18 has a second coding stage 30 and a third coding stage 31 in addition to the first coding stage 12. The three encoding stages 12, 30, 31 allow three different encoding methods. Therefore, in this case, the processing means 18 is designed to process the response signal RS by three different coding methods. However, it is possible to provide only two coding stages or four or more coding stages. The difference between these coding methods possible with the three coding stages 12, 30, 31 is that the assignment of a specific sequential signal sequence to a specific logic bit (1 or 0) depends on the coding method. Is different. The fact that a specific sequential signal sequence is assigned to a specific logic bit has long been known as an “extended spectrum” transmission method.

  The three coding stages 12, 30, 31 can be controlled by the control coupling means 25 as a function of two representative values REP1 and REP2 that can be determined by the determining means 22. In this case, the control means 26 can activate the encoding stage 12 or 30 or 31 as a function of each of the two representative values REP1 and REP2, so that in each case one encoding method can be executed. Each activated coding stage 12 or 30 or 31 sends the coded response signal CRS1 or CRS2 or CRS3 generated by each coding to the modulation stage 13. The modulation stage 13 then sends each response signal MCRS1, MCRS2 or MCRS3, which is modulated and coded, to the transmission means 3 for transmission to the communication station.

  Thus, the data carrier 1 and circuit 2 in FIG. 2 allow the coding stage 12 or 30 or 31 activated at any one time to be activated as a function of the two representative values REP1 and REP2, As a result, the coding stage 12 or 30 or 31 activated at any one time, and thus the coding method performed at any one time, depends on the value of the field strength acting on the data carrier 1 Will. This allows the data carrier 1 exposed to different field strengths to transmit response signals for these different field strengths to the communication station using different coding methods, and as a result, the communication station uses different coding methods. Since it becomes possible to distinguish the response signals based on these, it is ensured that these response signals can be completely detected.

  The data carrier 1 and the circuit 2 in FIG. 3 further include processing means 18 with different designs. In this case, the processing means 18 is designed to process the response signal RS with two different subcarrier signals SCS1 and SCS2. However, the processing means 18 may be designed to process the response signal RS with more than two different subcarrier signals SCS1 and SCS2, for example, three or four types of subcarrier signals. Response signal RS can be modulated by two subcarrier signals SCS1 and SCS2. These two different subcarrier signals SCS1 and SCS2 have different frequencies, that is, subcarrier frequencies. Subcarrier signal generation means 32 is provided for generating two subcarrier signals SCS1 and SCS2. The subcarrier signal generating means 32 is in the form of a frequency-switchable subcarrier signal generator capable of sending control data CDA from the control means 26 to it. The frequency of the subcarrier signal generator can be switched over as a function of the transmitted control data CDA. The control data CDA is generated as a function of the two representative values REP1 and REP2 and as a function of the random number generated by the random number generator 27 in a manner similar to that in the data carrier 1 of FIGS. . Accordingly, the two subcarrier signals SCS1 and SCS2 having different frequencies can be generated as a function of the two representative values REP1 and REP2 by the subcarrier signal generation means 32.

  Therefore, the modulation stage 13 sends out different modulation results for different field intensities acting on the data carrier 1 by means of the data carrier 1 and the circuit 2 in FIG. Can be transmitted from the data carrier 1 to the communication station. It is also ensured that the data carriers that are exposed using transmission signals that are exposed to different field strengths and therefore differently modulated will be completely distinguishable and therefore fully detectable. This is because data carriers exposed to different field strengths respond to the communication station using transmission signals MCRS4 or MCRS5 subjected to different modulations, so that no masking effect is lost as described above.

  By means of the data carrier 1 and the circuit 2 described above, two representative values REP1 and REP2 are formed in each case. However, a solution in which only one representative value is formed, that is, either the representative value REP1 or the representative value REP2, is possible, and it is not necessary to do so. However, if necessary, more than two representative values may be formed, for example three or four representative values.

  It should be mentioned that the time slot is defined as a function of the random number generator and that different transmission parameters (eg the subcarrier frequency of the subcarrier signal) are varied as a function of the field strength acting on the data carrier 1. It is also possible to combine with.

  FIG. 4 shows the communication station 40. The communication station 40 is intended and designed to perform non-contact communication with the data carrier 1 of FIG. That is, the communication station 40 is designed to perform contactless communication with a data carrier in which transmission signals are transmitted to the communication station 40 within different time windows.

  In this case, the communication station 40 has sequence control means 41 provided by a microcomputer. However, the sequence control means 41 may be in the form of a logic circuit connected by wiring. A clock signal generator 42 for sending the clock signal CLK to the sequence control means 41 is coupled to the sequence control means 41.

  Command signal generation means 43 is coupled to the sequence control means 41. The command signal generating means 43 can generate a plurality of command signals (for example, an inquiry signal, a selection signal, a read command signal, a write command signal, and some other command signals). In the case of FIG. 4, the inquiry signal IS represents all command signals.

  Coding means 44 that functions to code the sent command signal is coupled to the output side of the command signal generating means 43. After encoding, the encoding means 44 produces an encoded command signal (eg, an encoded inquiry signal CIS). A modulation means 45 is coupled to the output side of the encoding means 44. The modulating means 45 can be sent a coded command signal (eg, a coded inquiry signal CIS) and can further send a carrier signal CS generated by the carrier signal generator 46. Since the modulation means 45 can modulate the supplied carrier signal CS as a function of the supplied coded command signal as well, after modulation, the modulation means 45 can generate a modulated coded command signal (e.g. A modulated coded interrogation signal MCIS). Amplifying means 47 capable of amplifying the modulated coded command signal is coupled to the output side of modulating means 45. Adapter means 48 is coupled to the output side of the amplifying means 47. On the output side of the adapter means 48, a transmission means 49 having a transmission coil 50 and operating as both transmitter means and receiving means is coupled. The modulated coded command signal amplified by the amplifying means 47 is sent to the transmission means 49 via the adapter means 48 and all of the data carriers 1 in FIG. 1 existing within the communication range of the communication station 40. Is transmitted.

  The circuit elements that have been described so far function to transmit signals from the communication station 40 to the data carrier 1 of FIG. The communication station 40 is also provided with means for operating when a transmission signal is transmitted from the data carrier 1 of FIG. 1 to the communication station 40. These means also include transmission means 49 and adapter means 48.

  These means further include processing means 51 that can process the transmission signal (eg, the modulated coded response signal MCRS transmitted from the data carrier 1 of FIG. 1 to the communication station 40). . The processing means 51 has filter means 52 coupled to the adapter means 48, and the demodulation means 53 is coupled to the output side of the filter means 52, and the decoding means 54 is coupled to the output side of the demodulation means 53. ing. Each transmission signal is filtered by the filter means 52, demodulated by the demodulation means 53, and then decoded by the decoding means 54. As a result, when the modulated coded response signal MCRS is transmitted to the communication station 40, the coded response signal CRS appears from the demodulation means 53 and the response signal RS appears from the decoding means 54.

  On the output side of the processing means 51, a transmission parameter detection means 55 and a transmission signal detection means 56 are coupled. In this case, the transmission parameter detection means 55 is a time window detection means. This time window detection means transmits a transmission signal (for example, the response signal RS transmitted to the communication station 40) in any time window TWn out of a total of 64 possible time windows TW starting at different times. Can be detected.

  The transmission signal detection means 56 is intended to detect the content of the transmission signal and is designed as such. For example, the transmission signal detection means 56 can detect the content of the response signal RS. This content may be, for example, a serial number of the data carrier 1 and data stored in the data carrier 1 representing, for example, product type, product price, date of manufacture, and similar characteristics. The data DAT detected by the transmission signal detection means 56 is sent to the sequence control means 41 and controlled by the sequence control means 41 and relayed for further processing (here, for example, to a so-called host computer). Sent).

  The transmission parameter detection means 55 is designed to generate information data INFO. The information data INFO in each case represents a transmission parameter indicating the characteristics of the particular transmission signal received, so in this case the time during which the transmission signal was transmitted from the data carrier 1 to the communication station 40. The transmission parameter which shows the characteristic of a window is represented. It should be noted here that each time window in which the transmission signal is transmitted from the data carrier 1 in FIG. 1 to the communication station 40 depends on the field strength acting on the data carrier 1 in FIG. The value of the field strength varies as a function of the distance of the data carrier 1 from the communication station 40.

  The information data INFO generated by the transmission parameter detection means 55 can be sent to the sequence control means 41. The sequence control means 41 has a determination means 57. This determining means 57 is advantageously provided between the transmission parameter detecting means 55 and the command signal generating means 43. The decision means 57 is designed to generate decision data DDA as a function of the information data INFO received from the transmission parameter detection means 55 and to send this decision data DDA to the command signal generation means 43. Using the decision data DDA, it is possible to inform the command signal generating means 43 which command signal from the entire set of command signals that can be generated can be generated by the command signal generating means 43. This provides the advantage that the command signal generating means 43 receives from the determining means 57 an approval for generating a specific command signal. The information data INFO sent to the decision means 57 depends on the transmission parameters detected at any one time (ie in this case the time window detected at any one time) and therefore the specific transmission It depends on the value of the field strength acting on the data carrier that has transmitted the signal to the communication station 40. This means that the command signal generating means 43 generates only a command signal that can be significantly transmitted to the data carrier. This would mean, for example, that no write command signal is transmitted to the data carrier 1 which is relatively remote from the communication station 40 and is therefore only acting at a low field strength. This is because, in order to execute such a writing process activated by such a write command signal, a relatively high power is required. This is because it is almost impossible to use the data carrier 1 located far away, so that a complete writing process cannot be ensured.

  In the case of a communication station that performs non-contact communication with the data carrier 1 in FIG. 2 (this communication station is not shown), the transmission parameter detection means and the transmission signal detection means are provided in the same manner. The transmission of the transmission signal from the two data carriers 1 to the communication station is designed to detect the coding method performed thereby. A further object in this case is that once the transmission parameter detection means detects which transmission parameter is used to transmit the transmission signal to the communication station, the transmission parameter detection means sends control information to the transmission signal detection means. The transmission parameter detection means interacts with the transmission signal detection means so that the transmission signal detection means can completely detect the transmission signal transmitted to the communication station using this control information.

  In the case of a communication station for contactless communication with the data carrier 1 of FIG. 3 (also not shown), transmission parameter detection means and transmission signal detection means are still provided, but transmission parameter detection means are modulated. The subcarrier frequency used for the transmission signal is detected, and the modulated and coded transmission signal is consequently sent to the transmission parameter detection means, and the detection of this transmission parameter is sent to the demodulation means in the processing means. By influencing, it is designed to ensure that the modulated coded transmission signal is completely demodulated according to the detected modulation conditions.

  In the case of data carrier 1 and circuit 2 in FIGS. 2 and 3 described above, an optimal amplitude-modulated and coded interrogation signal IS is transmitted from the communication station to the associated data carrier 1, resulting in a response. The signal RS is generated immediately in the data carrier 1. Both the inquiry signal IS and the response signal RS take the form of a defined length data word. However, in order for the interrogation signal to take the form of an unmodulated start signal generated by the communication station, this start signal is essentially a sinusoidal signal with no information content, and the start signal is The data carrier is powered by being emitted by the communication station using the transmission means of the communication station within the communication range of the communication station and received by the transmission means of the data carrier that falls within the communication range of the communication station. And the generation of the response signal can be triggered automatically by the data carrier generating means.

1 is a schematic diagram in the form of a block circuit diagram of what is an essential part of the data carrier and the circuit for this data carrier of the first embodiment of the invention herein; FIG. The essential parts of the data carrier and the circuit for the data carrier of the second embodiment of the invention in the present specification are shown in the same manner as in FIG. The essential parts of the data carrier and the circuit for the data carrier of the third embodiment of the present invention in this specification are shown in the same manner as in FIGS. 1 is a schematic diagram in the form of a block circuit diagram of what is an essential part of a communication station of one embodiment of the present invention herein; FIG.

Explanation of symbols

1 ... Data carrier
2 ... Circuit for data carrier
3 ... Reception stage
6 ... Contact terminal
12 ... First coding stage
17 ... Generation stage
18 ... Processing circuit
19 ... Time window definition means
22 ... Determining device
25 ... Control coupling
26 ... Control means
30 ... Second coding stage
31 ... Third coding stage
32 ... Subcarrier signal generation means
40 ... Communication station
43 ... Command signal generation means
49 ... Receiving means
51 ... Processing means
55 ... Transmission parameter detection means
57 ... Deciding means

Claims (12)

A data carrier for contactless communication with a communication station, the means listed below:
Receiving means for receiving an interrogation signal that can be generated by the communication station and that can be transmitted to the data carrier in a contactless manner by a field produced by the communication station and acting on the data carrier;
Generating means for generating a response signal as soon as the inquiry signal is received;
The response signal is designed to process the response signal into a transmission signal suitable for transmission to the communication station, and at least one transmission parameter of the transmission signal can be changed therein. Processing means for
Determining means for determining at least one representative value representative of the field strength of the field acting on the data carrier;
Designed to controllably influence the processing means as a function of the at least one representative value, i.e. to change at least one transmission parameter of the transmission signal as a function of the at least one representative value. A control coupling means between the determining means and the processing means;
Having a data carrier.   Interacting with the determining means designed to generate control data as a function of the at least one representative value, and changing the at least one transmission parameter of the transmission signal according to the generated control data 2. A data carrier according to claim 1, wherein control means for interacting with said processing means are provided in said control coupling means for the purpose. The processing means is designed to process the response signal within at least two time windows starting at different starting points; and
The processing means comprises, for this purpose, time window defining means capable of defining at least two different starting points for the time window as a function of the at least one representative value;
3. A data carrier according to claim 1 or claim 2. The processing means is designed to process the response signal using at least two different encoding methods; and
The processing means is for this purpose at least two coding methods designed to perform different coding methods, which can perform at least two different coding methods as a function of the at least one representative value. Having a stage,
3. A data carrier according to claim 1 or claim 2. The processing means is designed to process the response signal using at least two different subcarrier signals capable of modulating the response signal; and
For this purpose, the processing means comprises subcarrier signal generation means capable of generating at least two different subcarrier signals as a function of the at least one representative value,
3. A data carrier according to claim 1 or claim 2. A circuit for a data carrier for performing contactless communication with a communication station, the means listed below:
Can be generated by the communication station and transmitted to the data carrier in a contactless manner by a field created by the communication station and acting on the data carrier, and therefore transmitted to the circuit for the data carrier A coupling means for receiving an interrogation signal;
Generating means for generating a response signal as soon as the inquiry signal is received;
The response signal is designed to process the response signal into a transmission signal suitable for transmission to the communication station, and at least one transmission parameter of the transmission signal can be changed therein. Processing means for
Determining means for determining at least one representative value representative of the field strength of the field acting on the data carrier;
Designed to controllably influence the processing means as a function of the at least one representative value, i.e. to change at least one transmission parameter of the transmission signal as a function of the at least one representative value. A control coupling means between the determining means and the processing means;
A circuit for a data carrier for performing contactless communication with a communication station.   Interacting with the determining means designed to generate control data as a function of the at least one representative value, and changing the at least one transmission parameter of the transmission signal according to the generated control data 7. A circuit according to claim 6, wherein control means for interacting with said processing means are provided in said control coupling means. The processing means is designed to process the response signal within at least two time windows starting at different starting points; and
The processing means comprises, for this purpose, time window defining means capable of defining at least two different starting points for the time window as a function of the at least one representative value;
The circuit according to claim 6 or 7. The processing means is designed to process the response signal by at least two different encoding methods; and
The processing means is for this purpose at least two coding methods designed to perform different coding methods, which can perform at least two different coding methods as a function of the at least one representative value. Step,
8. The circuit according to claim 6 or claim 7, comprising: The processing means is designed to process the response signal using at least two different subcarrier signals capable of modulating the response signal; and
For this purpose, the processing means comprises subcarrier signal generation means capable of generating at least two different subcarrier signals as a function of the at least one representative value,
The circuit according to claim 6 or 7. A communication station for contactless communication with a data carrier,
The data carrier is designed for contactless communication with the communication station, and the following means:
Receiving means for receiving an interrogation signal that can be generated by the communication station and that can be transmitted to the data carrier in a contactless manner by a field produced by the communication station and acting on the data carrier;
Generating means for generating a response signal as soon as the inquiry signal is received;
The response signal is designed to process the response signal into a transmission signal suitable for transmission to the communication station, and at least one transmission parameter of the transmission signal can be changed therein. Processing means for
Determining means for determining at least one representative value representative of the field strength of the field acting on the data carrier;
So as to controllably influence the processing means as a function of the at least one representative value, i.e. to change the at least one transmission parameter of the transmission signal as a function of the at least one representative value. A designed control coupling means between the determining means and the processing means;
Have
The communication station is
Command signal generating means for generating a command signal;
Receiving means for receiving the transmission signal transmitted from the data carrier to the communication station;
Processing means for processing the received transmission signal;
Transmission parameter detection means for detecting the transmission parameter of the received transmission signal;
An object is to make a decision to interact with the transmission parameter detection means and to generate at least one command signal as a function of the transmission parameters of the received transmission signal detected by the transmission parameter detection means. And a determination means designed in such a way;
A communication station for performing contactless communication with a data carrier. The determining means is
Provided between the transmission parameter detection means and the command signal generation means, and
Designed to affect the command signal generation means as a function of the transmission parameter of the received transmission signal detected by the transmission parameter detection means, which command signal is generated by the command signal generation means Have a relationship with whether it will be possible,
The communication station according to claim 11.